In order to treat a lesion area appearing in a living body lumen such as blood vessels, biliary ducts, bronchial tubes, esophagi, and urethrae, stent treatment has been performed in which a stent is caused to indwell in the living body lumen by delivering the stent using a stent delivery device.
For example, JP-T-2008-507376 discloses a stent which is interposed between a sheath (cover) and a shaft (holder) in a contracted state of the sheath when the stent is delivered into the living body lumen, and which self-expands when the stent is exposed in a lesion by the sheath moving rearward. A rivet is attached to an end portion of the stent so that the stent does not follow the rearward movement of the sheath when the stent is exposed. The rivet is attached so as to protrude relative to an inner surface and an outer surface of the stent, and is locked by a ridge portion of the shaft. In this manner, a restriction (position stopping) on the stent moving along the shaft is imposed.
Incidentally, since the rivet protrudes beyond the inner side of the stent, interference with the flow of a body fluid after the stent indwells in the living body lumen can occur. For this reason, it can be desirable to set a protruded amount of the rivet to be as little as possible. However, in this case, the rivet is easily unlocked by the ridge portion, thereby leading to a disadvantage in that the stent is forced to follow the movement of the sheath.
In addition, although not disclosed in JP-T-2008-507376, the above-stent is exposed, thereby causing a possibility of poor indwelling of the stent. Accordingly, in a case of the stent treatment, if the stent is misaligned when exposed, the sheath is switched from the rearward movement to the forward movement so as to perform an operation for returning the stent into the sheath again. Therefore, it is desirable to adopt a configuration in which the stent does not follow bidirectional (rearward and forward) movement of the sheath.